A conventional winding method of a stator for rotation detector is disclosed in Patent Literature 1. FIG. 9 is a configuration of the winding method of a stator shown in Patent Literature 1. In this method, output winding 101 and output winding 102, which are different in phase from each other, are wound around slots defined by the adjacent magnetic poles. Output winding 101 is wound around every other slot. Output winding 102 is wound around all slots over output winding 101. Then, output winding 101 is wound over output winding 102 around the slots that do not have output winding 101 as the undermost layer. When the windings around the slots are viewed in cross section, the order of winding output windings 101 and 102 is alternated from one slot to the next. In FIG. 9, the conventional stator for rotation detector includes stator core 103.
According to this method, output windings 101 and 102 can be misaligned so as to reduce variation between output signal A from output winding 101 and output signal B from output winding 102, thereby having high detection accuracy of a rotation angle.
There are, however, following problems with the aforementioned winding method of Patent Literature 1.
In the rotation detector of this type, in principle, the output signals have different amplitudes depending on their rotation angles. Therefore, the number of turns of the output windings around the slots needs to be varied sinusoidally. This causes the contribution to the flux linkage between these output windings to be different from slot to slot. As a result, the winding method of Patent Literature 1 has limitations in reducing the imbalance of contribution to the flux linkage between these output windings.
More specifically, assume that output winding 101 has the same number of turns in all slots, and output winding 102 also has the same number of turns in all slots. Then, the contribution to the flux linkage can be equalized between output windings 101 and 102 in all slots by alternating the order of winding them from one slot to the next, thereby reducing variation between the output signals. In the rotation detector of the present invention, however, the number of turns of each output winding around the slots needs to be varied sinusoidally as described above. Thus, since the number of turns of each output winding differs from slot to slot, it is difficult to equalize the contribution to the flux linkage between output windings 101 and 102 only by alternating the order of winding them from one slot to the next.    Patent Literature 1: Japanese Patent No. 3681167